Risk Factors for Pregnancy During Adolescence in a Case-Control Study in Northern Mexico

Early child bearing is highly prevalent in Mexico. We conducted an exploratory case-control study among sexually active teenage girls in Ciudad Juarez, Chihuahua, a large (1.7 million) city in the Mexico-Texas-New Mexico border, with teen fertility rate of 80 births per 1,000 women. Cases were currently pregnant 15-19 year-olds looking for prenatal care at nine health care facilities. Controls were self-reported sexually active 15-19 year-olds girls without a history of pregnancy selected through a household sampling survey. Through this household survey 20 pregnant teenagers were identified and recruited to the study. In total, 48 cases and 48 controls were selected. Not using any contraceptive method was independently associated with the risk of teenage pregnancy (Odds Ratio=2.8; 95% CI: 1.1, 7.6) after controlling for marital status, access to health care, age, and frequency of sexual intercourse. This factor explained 39% of cases. However, being married or living with partner, lacking of a health plan and reporting more than 2+ sexual intercourses per week, explained 57%, 31% and 27% of cases, respectively. Not using contraceptive methods is likely to be a common preference: among the controls, 38% of sexually active female teenagers were married or living with their partners, which along with findings of focus groups we conducted seem to indicate that early childbearing is a prevalent expectation in this population. If prevention programs were to succeed they will need to target early education to change prevalent attitudes and beliefs.